Search results for "DASE"
showing 10 items of 1891 documents
Acyl-Chain Mismatch Driven Superlattice Arrangements in DPPC/DLPC/Cholesterol Bilayers
2010
Fluorescence and infrared spectroscopy and cholesterol oxidase activity were employed to investigate the effect of phosphatidylcholine (PC) acyl chain length mismatch on the lateral organizations of lipids in liquid-ordered dipalmitoyl-PC/dilauroyl-PC/cholesterol (DPPC/DLPC/CHOL) bilayers. Plots of steady-state fluorescence emission anisotropy of diphenylhexatriene (DPH) labeled PC (DPH-PC) embedded in the DPPC/DLPC/CHOL bilayers revealed significant peaks at several DPPC mole fractions (Y(DPPC)) when the cholesterol mole fraction (X(CHOL)) was fixed to particular values. Analogously, the DPH-PC anisotropy peaked at several critical X(CHOL)'s when Y(DPPC) was fixed. Acyl chain C-H and C hor…
Mode of action of Bacillus thuringiensis PS86Q3 strain in hymenopteran forest pests
2001
The mode of action of Cry toxins has been described principally in lepidopteran insects as a multistep process. In this work we describe the mode of action of a Cry toxin active in the common pine sawfly Diprion pini (Hymenoptera, Diprionidae), considered a major forest pest in Europe. Strain PS86Q3 contains a long bipyramidal crystal composed of five major proteins. The N-terminal sequence shows that the 155 kDa protein corresponds to Cry5B toxin and the other proteins belong to the Cry5A subgroup. PCR analysis indicates the presence of cry5Ac and cry5Ba genes, suggesting that Cry5A protein should be Cry5Ac. Activation of protoxins with trypsin or with midgut content from D. pini and Cepha…
Oxidation of dobutamine and dopamine by horseradish peroxidase
2022
Dobutamine and dopamine have been previously shown to interfere with enzymatic diagnostic tests and different mechanisms responsible for this effect have been postulated. We have studied the oxidation by horseradish peroxidase (HRP) of dopamine, dobutamine, and its analog with the phenol group blocked by methylation. Oxidation of dobutamine was much faster than dopamine, as reported before, whereas the methylated analog of dobutamine was oxidized at intermediate rate. This demonstrates that the phenol group in dobutamine is oxidized preferentially by HRP and acts as an electron-transfer mediator in oxidation of the catechol group. Different oxidation rates of catechol groups in dopamine and…
Comparison of DPP‐4 inhibition versus GLP‐1 analogue supplementation on survival and vascular complications in experimental sepsis (145.2)
2014
Background: Dipeptidyl peptidase [DPP]-4 inhibitors are a new class of drug for the treatment of hyperglycemia and recent studies revealed anti-inflammatory effects of these gliptins in experimenta...
Selected cytotoxic gold compounds cause significant inhibition of 20S proteasome catalytic activities
2014
Abstract Six structurally diverse cytotoxic gold compounds are reported to cause profound and differential inhibition of the three main catalytic activities of purified 20S proteasome whilst auranofin , an established gold(I) drug in clinical use, is nearly ineffective. In particular, the gold(I) complex [( pbiH ) Au ( PPh 3 )] PF 6 , turns out to be the most potent inhibitor of all three enzyme activities with sub-micromolar IC 50 values. The present results further support the view that proteasome inhibition may play a major – yet not exclusive – role in the cytotoxic actions of gold based anticancer agents.
Inkjet printing methodologies for drug screening
2010
We show for the first time a contactless, low-cost, and rapid drug screening methodology by employing inkjet printing for molecular dispensing in a microarray format. Picoliter drops containing a model substrate (D-glucose)/ inhibitor (D-glucal) couple were accurately dispensed on a single layer consisting of the enzymatic target (glucose oxidase) covalently linked to a functionalized silicon oxide support. A simple colorimetric detection method allowed one to prove the screening capability of the microarray with the possibility to assay with high reproducibility at the single spot level. Measurements of the optical signal as a function of concentration and of time verified the occurrence a…
Injectable in situ forming microgels of hyaluronic acid-g-polylactic acid for methylprednisolone release
2013
Abstract A hydrophobic derivative of hyaluronic acid (HA), obtained by grafting polylactic acid (PLA) to the polysaccharide, has been exploited to produce injectable in situ forming microgels. First of all, self assembling properties of HA-g-PLA copolymer have been evaluated by determining the critical aggregation concentration (CAC) value, then this copolymer has been dissolved in a mixture water/NMP 5:2 v/v with a concentration greater than CAC. When solutions at 1% or 2% w/v were injected into Dulbecco phosphate buffer solution (DPBS) pH 7.4, microgels promptly are formed. Their stability in DPBS pH 7.4 in the absence or in the presence of hyaluronidase and cell compatibility have been e…
Interferon-alpha 2a increases serum concentration of hyaluronic acid and type III procollagen aminoterminal propeptide in patients with chronic hepat…
1994
Interferon-alpha (IFN-alpha) has become an important drug for the treatment of chronic viral liver diseases. However, the action of IFN-alpha remains unclear. We investigated whether human recombinant IFN-alpha modulates serum concentrations of hyaluronic acid (HA) and type III procollagen aminoterminal propeptide (P-III-NP) in 56 patients with chronic hepatitis-B under IFN-alpha therapy. IFN-alpha increased the HA serum level in 44 of 46 patients and, after cessation of treatment, HA serum levels returned to the pretherapy levels. The increase of HA serum level was higher in patients with active cirrhosis (aC) than in patients with chronic persistent hepatitis (CPH) and in patients with se…
A peptide inhibiting the collagen binding function of integrin alpha2I domain.
1999
Integrin alpha2 subunit forms in the complex with the beta1 subunit a cell surface receptor binding extracellular matrix molecules, such as collagens and laminin-1. It is a receptor for echovirus-1, as well. Ligands are recognized by the special "inserted" domain (I domain) in the integrin alpha2 subunit. Venom from a pit viper, Bothrops jararaca, has been shown to inhibit the interaction of platelet alpha2beta1 integrin with collagen because of the action of a disintegrin/metalloproteinase named jararhagin. The finding that crude B. jararaca venom could prevent the binding of human recombinant ralpha2I domain to type I collagen led us to study jararhagin further. Synthetic peptides represe…
Hydrolytic enzymes in the coelomic cells of the polychaeteNereis virens during sexual maturation
1991
Nereis virens were collected between April 1989 and April 1990 at Yerseke, Oosterscheldt Bay, The Netherlands. Activities of the hydrolytic enzymes arylsulfatase, acid phosphatase, N-acetylglucosaminidase, aminopeptidase, and carboxylesterase were investigated in coelomic cells (elaeocytes) of individuals at different stages of maturation as determined by the time course of oocyte growth. On a protein-content basis, up to ten-fold higher specific activities were present in the elaeocytes compared to the body-wall tissue. Acid phosphatase, N-acetylglucosaminidase, leucine aminopeptidase, and long- and medium-chain esterase increased continuously from the beginning to the later stage of sexua…